Virtual Server 2005 and PIIX Firewalls

[swhich]

Hi All,
I am having problems with my Vitrual Server guest OS passing information across a PIX firewall. This does not appear to be an issue with the firewall as I can run VMWare server on the same physical host, start the Virtual Server image on VMware and everything works. However when I start the image under MS Virtual Server all network traffic is blocked by the Firewall. Has anybody seen anything like this?

I know that the Virtual Server guest is connected to the network as the DHCP server is on the other side of the firewall and the guest OS is getting a DHCP address via DHCP relay. All Windows firewall functionality on both the guest and host is disabled.

Any ideas would be great appreciated.

 

[Roadki11]

I havent used MS's virtual server but i know VMWare by default sets up the guest nic in bridge mode with the host nic. i wonder if MS VS is doing something just a bit different, like setting it up in a NAT by default or some such thing.